Transforming amino acid production

An international team of researchers led by NUS Chemical and Biomolecular Engineering Assistant Professor Yan Ning has invented a novel and sustainable chemical approach that can rapidly produce amino acids from woody or plant-based biomass, such as grass, straw and wood chips from agricultural wastes.

Amino acids are essential for the production of proteins and have wide-ranging industrial applications. They are used in human and animal feed, and as an intermediate compound to produce biodegradable plastics, cosmetics and pharmaceutical products.

Amino acids are primarily produced through microbial cultivation processes — such as fermentation — which are costly, time-consuming and require extensive separation processes. Current conventional chemical approaches also employ highly toxic chemicals and non-renewable organic compounds.

The researchers’ new method involves breaking down glucose derived from the plant-based biomass to lactic acid which is then converted into an amino acid with the help of a synthetic catalyst created by Asst Prof Yan’s team. The innovative chemical system can convert about 40 per cent of the extracted glucose into amino acids in only a few hours and can potentially completely convert all the extracted glucose, unlike microbial cultivation processes where a substantial amount of glucose is consumed for growth of the microorganisms.

Our new method is much faster and more stable and sustainable than current microbial cultivation processes as it does not need to rely on microorganisms or bacteria that require strict sterile conditions for the lengthy conversion of glucose into amino acids and agricultural wastes may be used as a form of cheap and sustainable starting raw material.

— Asst Prof Yan Ning, NUS Chemical and Biomolecular Engineering

The team has shown that the system is capable of producing at least six types of amino acids, including leucine, alanine, aspartic acid and phenylalanine.

Asst Prof Yan said that their chemical system is able to produce amino acids that are of high quality, and comparable with those produced by conventional microbial cultivation processes.

“Our new method is much faster and more stable and sustainable than current microbial cultivation processes as it does not need to rely on microorganisms or bacteria that require strict sterile conditions for the lengthy conversion of glucose into amino acids and agricultural wastes may be used as a form of cheap and sustainable starting raw material. Moreover, the remaining woody biomass left behind after the glucose extraction can be further processed into products such as pulp and paper,” he explained.

Asst Prof Yan and his team are working to develop even more varieties of amino acids that are high in industry demand.

The work is a collaboration with Professor Wang Ye’s research group at Xiamen University, along with scientists from Kyoto University in Japan; King Abdullah University of Science and Technology in Saudi Arabia; National Renewable Energy Laboratory in the US; and the Institut des Sciences et Ingénierie Chimiques in Switzerland.

The team’s research findings were published in the Proceedings of the National Academy of Sciences of the United States of America earlier this year.